Punch-press safety appliance



1,519,369 0. A. ELMER PUNCH PRESS SAFETY APPLIANCE Filed Dec. 21, 1921 3 Sheets-Sheet 1 I]- Annex-T Elmer gnmntoz atto'z waif Dec.16,-1924. 1,519,369

' I o. A. ELMER PUNCH PRESS SAFETY APPLIANCE Filed Dec. 21, 1921 s Sheets-Shet 2 EL Amer: Elmer gwumdoz Dec. 4- I 1,519,369

o. A. ELMER PUNCH PRESS SAFETY APPLIANCE Filed Dec. 21, 1921 3 Sheets-Sheet 5 Jig- 5- Patented Dec. 16, 1924.

UNITED- STATES-1 OIBAD-IAH ALBERT ELMER, OF OGD-ENSBURG,- NEW YORK.

PUNCH-PRESS SAFETY APPLIANCE.

Application filed December 21, 1921. Serial No. 523,953.

To all whom; it may concern:

Be it known that I, O'BADIAH ALBERT Emma, a subject of the King of Great Britain, residing at Ogdensburg, in the county of Saint Lawrence, State of New York, have: invented certain new and useful Improvements in Punch-Press Safety Appliances, of which the following is a speci fication.

Thisinven-tion relates to attachments for presses of the power ty e, and the primary object of the invention is to provide improved safety appliance for preventing the accidental operation of the press, thereby eliminating any accident which might result from this contingency.

Another object of the im en-t'ion is the provision of a. novel means for engaging the operating rod of foot treadle', so as to prevent 'movement of the operating rod and the consequent actuation of the clutch mechanism of the press, when the foot trea-dle is inadvertently actuated by the op erator of the press or persons passing by the press.

A further object of the invention is theprovision of an automatic safety device for power presses embodying a sliding latching bar, which is normally urged in the path of an abutment carried by the treadle rod of the press, said latch being manually operated and disposed adjacent to the: bed of the press, whereby the same can be. conveniently actuated by the operator of the press when the foot treadle is depressed.

A still further object of the invention is the provision of a novel safety appliance for power presses, which is adapted to be incorporated with an ordinary type of press, requiring no change to the press structure or to the treadle o erating means for the clutch, said safety appliance being of simple and durable construction and adapted to be built into the press at the time of manufacture thereof or connected with presses already in use and on the market.

Vith these and other objects in view, the invention consists in the novel construction, arrangement and. formation of parts, as will be hereinafter more specifically described, claimed and illustrated in the accompanying drawings, forming a part of this specification, in which drawings:

Figure 1 is a fragmentary side elevation of a press showing; apart of the press mechan-ismin section, illustrating the novel safety appliance connected therewith.

Figure 2 is a similar view showing the safety appliance inits actuated position and the foot treadle in its actuated position.

Figure 3 is an enlarged elevation of the improved safety appliance, showing the catch member associated with the treadle operating rod.

Figure at is a longitudinal section through the" improved safety appliance, taken on the line 49-4 of Figure 8'.

Figure 5 is an enlarged fragmentary elevation of a portion of the latching bar, showing'the means of" connecting the latching head therewith, a portion of the head being shown insection.

Figure 6 is an enlarged detail perspective view of the oross'head carried by the operating rod for permitting the connection ofthe contractile coil spring thereto.

Referring to the drawings in detail, wherein similar reference characters designate corresponding parts throughout the several views, the letter A indicates a press; and B, the novel automatic safety appliance therefor.

The press A may be of the usual or any preferred type or character, but as shown the press is of the punch type, and includes the frame 10, the head 11 supporting the main drive shaft 12, the ram 13 which is operatively connected to the main drive shaft 12 and the bed 14. The drive shaft 12 has loosely mounted thereon the drive pulley or fly wheel 15 which is adapted to be connected to the drive shaft through the medium of the clutch mechanism 16 by the treadle mechanism 17. The clutch member 16 and the treadle mechanism 17 is of the ordinary or any preferred construction.

The treadle operating means 17 consistsof the connecting treadle rod 24 which has its upper end pivotally connected to a swinging lever 25, which is pivoted as at 26 to the head of the machine. This lever 25 is normally maintained in the path of the crank 21 carried by the clutch key 19 so as to prevent movement thereof under influence of the coil spring" 22. The lower end of the rod 245 is pivotally connected as at 27 to the ordinary type of treadle 28. It is obvious that when the trea'dle 28' is depressed the rod 2 f will be moved therewith, swinging the lever 25 from below the lower end of the crank 21, allowing the crank 21 to be rotated under the influence of the spring 22 and moving the eccentric key 19 to its looking position in relation to the shaft 12 and the pulley wheel 15.

The improved attachment B includes a base plate which can be connected to any preferred part of the press, by means of fastening elements 31- The base plate 30 is provided at spaced points with guides 32, 33, and 34. These guides are disposed in longitudinal alignment and are adapted to slidably support the sliding latch bar 35, the outer end of which is provided with a hand grip or handle 36. The base plate is preferably arranged on the machine in such a manner that the handle 36 will be disposed ata convenient point where an operator can readily grasp and actuate the same. The inner end of the latch bar carries the latchhead 37, which'may be made separate from the rod if so desired. An expansion spring 38 is coiled about the rod and engages the intermediate guide 33 and lock nuts 39, which are threaded on the bar. The bar 35 adjacent to its outer end is also provided with threads for the reception of nuts 40, which serve as means for engaging the opposite face of the guide 33 from the spring 38 in order to limit the inward movement of the rod under the influence of the spring 38. The lower forward end of the head 37 is bevelled as at 41 while its upper surface is formed flat for a purpose which will be hereinafter more fully described. The inner end of the base plate 30 is provided with a transversely extending guide 45 forming tracks for the reception of a slide block 46. This slide block 46 is preferably formed in two sections for clamping engagement with the treadle rod 24. The inner section of the slide block 46 which is designated by the numeral 47 is formed relatively large and is provided with guide flanges 48 for engaging under the guide tracks and the outer section is formed relatively small and designated by the reference character 49 and is connected with the relatively large section 47 by suitable machine screws 50. The meeting faces of the sections 47 and 49 are provided with polygonal shaped grooves 51 for the reception of the rod 24, and the portion of the rod which is disposed between the sections of the slide block 46 is preferably formed polygonal shaped in cross section as indicated by the reference character 52- The block carries an inwardly extending nose 53 on its outer side edge, which is adapted to normally rest upon the head 37 of the latch bar 35, and downward movement of the treadle 28 and the rod 24 is prevented by said latch bar and nose. The upper surface of the nose 53 is inclined or bevelled as at 54 and upon upward movement of the rod 24, the inclined surface 54 of the nose 53 will engage the inclined surface 41 of the head 37 of the latch 35 and thus automatically force the latch bar back and allow the treadle to resume its normal position.

In use of the improved safety appliance, when it is desired to actuate the press, the handle 36 is grasped and the latch pulled outwardly and the treadle 28 depressed in the ordinary manner. This will move the head 37 from out of the path of the nose 53 and allow thedownward movement of the treadle and the swinging of the lever 25 out of the path of the crank 21. This will permit the actuation of the crank and the eccentric key by the spring 22 and the driving connection between the fly wheel and the shaft will be established.

As soon as the treadle is operated, the latch is, of course, released, and upon the stopping of the press, it is merely necessary to release the treadle 28, which will automatically return to its normal position under the influence of the contractilecoil spring 55, which has its upper end connected to an eye 56 carried by one edge of the base plate 30 and its lower end connected to an eye 57 formed on a block 58. This block 58 is mounted upon the treadle rod 24, and is held in adjusted position thereon by. means of a set screw 59. WVhen the rod 24 resumes its normal position, the latch bar 35 will be automatically pushed inwardly owing to the formation of the nose 53 and the latch head 37 as heretobefore described. Upon the return movement of the treadle rod 24, the lever 25 will again be disposed in the path of the crank 21 and thus move the crank to its normal position and stop the actuation of the press.

From the foregoing, it can be seen that if the treadle is actuated inadvertently, in any way, the operation of the clutch mechanism 15 is absolutely precluded, and to permit the actuation of the press it is necessary to actuate the latch bar 35 as well as the treadle 28.

The device is of an exceptionally simple construction and can be readily incorporated with any type of press and so constructed and incorporated with the press in such a manner that no loss of time is encountered by the operator of the press in actuating the latch bar.

Changes in details may be made without departing from thespirit or scope of this invention; but, 7

I claim:

1. The combination with a power press including a frame, a bed, an operating shaft, a drive pulley wheel loosely mounted upon the shaft, means for establishing driving connection between the drive pulley wheel and the shaft, a treadle mechanism for operating said means for establishing driving communication between the pulley wheel and the shaft including a connecting rod, resilient means connected to said rod for normally urging the same in one direction of a safety appliance for the press for preventing the normal actuation of the treadle operating means including a base plate secured to the frame of the press adjacent to the bed, a latch bar slidably mounted on the base plate, a slide block adjustably secured to the rod, a guide mounted upon the base plate for receiving said slide block, an abutment formed on the slide block, spring means normally urging the latch bar into the path of the abutment for preventing movement thereof in one direction, a hand grip formed on the outer end of the latch bar and disposed in relatively close relation to the bed.

2. As a new article of manufacture, a

safety appliance for power presses comprising a base plate, longitudinally extending guides carried by the base plate, guide tracks carried by and extending transversely of the base plate adjacent to one end thereof, a sectional slide block carried by said guide tracks for adjustable clamping engagement with a connecting rod of the treadle mechanism of a press, an abutment formed on the slide block, a latch bar slidably carried by said guides, an operating handle formed on the outer end of the latch bar, a latch head formed on the inner end of the latch bar, spring means normally urging the head into engagement with the abutment for preventing movement of the abutment in one direction in said guide tracks, the 0pposite faces of the abutment and latch head being bevelled.

OBADIAH ALBERT ELMER 

